[Petronski]

I believe 190 is a surface highway, while 12 is a limited access freeway.

They want the causeway traffic out of New Orleans to proceed unimpeded onto the freeway (I12), while also avoiding a backup of the minor traffic coming westward to that point.

[ArmstedFragg]

Thanks... I knew there had to be a reason, just couldn’t work it out from the map. Gonna go check the satellite photos now...

[lainie]

Ah, that explains it well. Thanks!